<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>简单页面</title>
    <style>

        #header, #siderLeft, #siderRight, #footer {
            border: solid 1px #666;
            padding: 10px;
            margin: 6px;
        }

        #header {
            width: 500px;
        }

        #siderLeft {
            float: left;
            width: 60px;
            height: 100px;
        }

        #siderRight {
            float: left;
            width: 406px;
            height: 100px;
        }

        #footer {
            clear: both;
            width: 500px;
        }

        header, nav, article, footer {
            border: solid 1px #666;
            padding: 10px;
            margin: 6px;
        }

        header {
            width: 500px;
        }

        nav {
            float: left;
            width: 60px;
            height: 100px;
        }

        article {
            float: left;
            width: 406px;
            height: 100px;
        }

        footer {
            clear: both;
            width: 500px;
        }

    </style>
</head>
<body>
<div id="header">导航</div>
<div id="siderLeft">左边菜单区域</div>
<div id="siderRight">右边文本区域</div>
<div id="footer">底部说明</div>
<h1>使用位置专用标签进行优化</h1>
<header>导航</header>
<nav>左边菜单区域</nav>
<article>右边文本区域</article>
<footer>底部说明</footer>
</body>
</html>